21000022212220 has 24 divisors (see below), whose sum is σ = 44100441088704. Its totient is φ = 8399933752896.

The previous prime is 21000022212203. The next prime is 21000022212277. The reversal of 21000022212220 is 2221222000012.

It is a junction number, because it is equal to n+sod(n) for n = 21000022212194 and 21000022212203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2375827 + ... + 6902506.

It is an arithmetic number, because the mean of its divisors is an integer number (1837518378696).

Almost surely, 2^{21000022212220} is an apocalyptic number.

21000022212220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000022212220 is an abundant number, since it is smaller than the sum of its proper divisors (23100418876484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21000022212220 is a wasteful number, since it uses less digits than its factorization.

21000022212220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9391509 (or 9391507 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21000022212220 its reverse (2221222000012), we get a palindrome (23221244212232).

The spelling of 21000022212220 in words is "twenty-one trillion, twenty-two million, two hundred twelve thousand, two hundred twenty".